The objective of the project described below is to dramatically improve the capabilities of a class of micro electromechanical (MEMS) and micro optoelectromechanical (MOEMS) systems of great promise in areas where miniaturization of optics and machines is advantageous. Applications include emerging technologies such as holographic data storage for genomic and security databases, wavelength division multiplexing (WDM) and adaptive optics. The PI's propose to demonstrate, using an interesting MOEMS device, that techniques of nonlinear control theory will play a central role in future of this field.
Despite the fact that commercial applications of MOEMS are still in their infancy, notable successes like accelerometers in airbag deployment systems and digital micromirror arrays in high-end projection systems suggest a bright commercial future. This promise is accompanied by numerous interesting research problems, which are inherently cross-disciplinary.
A very promising device in this class is the electrostatically-actuated analog micromirror and micromirror array, used as a spatial light modulator (SLM). At the heart of these microfabricated devices is a small (<100 um square) mirror suspended by fixed springs and driven by applying an external voltage. While the micromirrors are interesting novelties, for them to reach their full commercial potential it is essential to control their displacements extremely precisely-within tens of nanometers or less. This poses a series of fascinating controls problems.
This proposal has four major objectives: 1. Fabricate micromirror SLMs, both individual and in arrays. 2. Develop control methodology suitable for governing micromirror actuation both with and without optical position feedback. This control serves both a stabilizing and tracking function. 3. Set up and implement optical testing and metrology capabilities for studying deflection properties on the subnanometer scale. 4. Actuate them using custom-designed on-chip electronics combined with off-chip commercial digital signal processors. Each of these objectives possesses several challenging problems in various research fields. The PI's preliminary results are very promising and they are confident that they can meet these objectives in this research program.
The team of researchers brought together under this proposal has the expertise necessary to carry out each of these objectives. Dr. Jordan Berg (Mechanical Engineering) will direct the proposal. He has expertise in control theory and in microfabrication. He will be primarily responsible for the fabrication of the micromirror devices, and closely work with the controls team. Dr. W. P. Dayawansa (Mathematics) is an expert in control theory. He will lead these efforts, and closely interact with the test team. Dr. Mark Holtz (Physics) works in microfabrication and optics. He will lead the optical test effort. This group is critically augmented by Dr. Richard Gale (Electrical Engineering, beginning 5/02). For the past ten years Dr. Gale has directed the development and commercialization of the Texas Instruments Digital Light Products (DLP) device. This is the world's most advanced commercial MOEMS device, the only commercialized micromirror array, consisting of over 700,000 micromirrors 12 um square, for high-end projection systems. Dr. Gale will lead the electrical test and work closely with the optical test and fabrication groups. While the emphasis areas are noted for each P.I., this network of interdisciplinary researchers will function together without boundaries to best achieve our proposed goals.
